Anotherpower.com Forum
Renewable Energy Questions/Discussion => Solar (heating or electric) => Topic started by: Norm on March 23, 2012, 08:58:00 pm
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A few solar cells from some Garden lights, I salvaged had
everything all set up....each one had a little NiCad (100Ma.)
So I was going to put 4 in series took all the wires off busted
at the soldered connection.....all but one right in the middle of
the series wire and solder lifted clean off....so when I attempted
to solder where the connection had been no thin little strand to
solder to.....how do they manage to expose and solder to this
silver strand in the first place?
....tried scaping with a razor blade just scraped everything off.....
Norm.
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What kind of solder did you try?
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You need at least two of the following things..
Young eyes
Enthusiasm
More solar cells
Or one of the following things...
Chinese manufacturing plant
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I've got some salvaged from the same thing. They appear to be printed directly on glass. With the
help of my best close-up glasses, it appears the solder joint is made with some kind of liquid solder.
Long story short, I just made up a small clamp, out of brass , kind of U shaped, and clamped the wire
on.
Not sure if that helps, or just confuses the issue, but good luck with it Norm.
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I'm pretty sure that a flux pen helps. I'm almost sure I watched a video on SunElec.com website about needing a flux pen made for solar panels or the connection job to a panel would be darn hard. I also wish you the best norm.
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I agree flux pen should help. In case you haven't, carefully cleaning it of old flux and debris from failed attempts is also a good idea.
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I bought a couple small cells years ago,
and they supplied 1" of 'special solder'.
Probably a different type of flux in the core.
It worked OK. Better than typical solder.
Good luck.
G-
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What kind of solder did you try?
The electrical type what I got from Walmart....works fine on soldering to
NiCad battery tabs.
Norm
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Might try holding the cells at a 45 degree angle so the solder rolls off.
Then just keep trying until you try 3' of solder.
It puts a lot of flux in the same place.
That is about the same concept as a flux pen.
G-
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Might try holding the cells at a 45 degree angle so the solder rolls off.
Then just keep trying until you try 3' of solder.
It puts a lot of flux in the same place.
That is about the same concept as a flux pen.
G-
Nice to know. Thanks for the tip G-
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Heat the surface instead of the solder.
Eventually, some stuff that looks like chrome will take solder.
Inversely, some 'powdered' looking silverish-looking stuff will take solder too.
Wires on a MorningStar SG-4 come to mind as an example, but eventually they will take, and wick, solder.
I wipe the powder off as well as possible before starting.
Other items will not take solder with normal solder.
AL light bulb bases come to mind. The solution in AL light bulb bases is to add solder to the existing solder.
In any case, it is important to keep the soldering iron tip clean and shiney.
The black gunk on the soldering iron tip is using up the flux in the solder's core.
G-
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I've seen stubborn tabs on PV before. On the Evergreen 3x6 cells back-plane they have a white non-metallic solder tab that will get poisoned by expended rosin build-up coming off the soldering iron - and then refuse to take-up a solder bond no matter what until its cleaned bright & new with isopropyl alcohol. Keeping the iron tip clean w/ bright fresh solder film by wiping with a wet paper towel helps too.
The surface you have the cells resting on should not soak up heat rapidly at all to get quick & clean solders. My favorite tool for holding tabbing and wires to the wafer is sliver of another wafer.
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The grey on the back is aluminium paste... cant solder to it.
The white "tabs" on the front and back are simply screen printed silver ink.
There is a problem here. The ink is temperature sensitive, so you need to solder to it, without being too hot or it will simply disappear.
If you scrape it it will just fall off as powder. I think it is a 2 pack conductive silver ink.
I find that if you put your rosin cored flux solder, between the tabbing tape and the white silver, and heat the tape, you get the best result without overheating the ink, and destroying it. ( the solder melts and the resin spreads at the right time... not too hot, not too cold.
If you have over heated the silver, it is useless, and you need to re track it with a similar product.
I don't know it the conductive inks you can get for your PCB's can take it's place.... but someone may know.
...............oztules
Edit: Also I find placing the hot iron tip directly on the white material is a good way to destroy it. Thats why we heat the tabbing from behind with resin and solder on the ink interface and move along at a reasonable speed.
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Oztules,
On these particular cells they had a transparent green coating
and you could see the silver streak (back side), at the factory,
they must have left a spot on either side uncoated (pos. and neg.)
so they could solder to the silver streak.....I think the wire came
loose along with the solder.....and the silver streak ! so it was
probably a lost cause....more trouble than it would be worth.
I was just practicing anyway....
No problem with the other three, the solder spots with the broken
wires embedded....I soldered the ribbons just like you said.....
A touch of flux on the solder spot then the tin on top and the solder
pen on top....easy enough.....have a cheap pencil soldering copper,
but I regulate the heat with an in line dimmer switch.
So I have about a dozen or so others that I can practice on.
Do you think that I could really make enough sets of these to be practical?
I was thinking of doing this on a small scale and gradually accumulating
them consisting of 5 or even 1 watt units.
I'm thinking of real conservative like $5.....$10 ::)
(okay.....stop laughing !.....it's not supposed to be That Funny )
Norm
Conneaut.....a nice sunny place to be .....today !
(even a little wind....) :)
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Norm, if you keep at it it will grow... mine is over 5kw ... one step at a time... over $3000 worth.
This link is to part of the solar cell story. Dave Ames does some good detail of how to make five dollar panels from bigger cells cut down. Much better way to do it I think. You know what your getting, and the price is right..... 50 cent picture frames and a few dollars of cells and eva.
Worth a look I think. http://www.fieldlines.com/index.php/topic,145004.50.html
...............oztules
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Norm,
If soldering temp is an issue,
might get a pack of "match melt solder" tabs things
from Radio Shack.
Its a pack of a couple/few dozen things,
maybe 3/16" x 5/8"? (I'm too lazy to go look right now)
It must be 2 think layers of solder (high Pb content?),
with a layer of flux between? I don't know.
But...
I can solder 2 stranded #18 or #16 wires together with 1 or 2 of those things and a match.
(a butane lighter works better, if you pay attention to where drips would land)
It even wicks up stranded wire to some extent.
My issue with it is it works too well.
Anything that works that easy MUST have a problem, right?
I don't know what the problem could be, except the composistion of the solder.
I would use it for stereo speaker wires, or in a car wire...
Not sure how far I'd trust it for 50 years...
"Anything that works that easy MUST have a problem, right?"
G-
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Ghurd, this is to acknowledge that I hear you but lot of times don't
have time to answer....if only I could even write half as fast as I
could read.....
but wait...that would make me a half fast writer....wouldn't it ? ::)
well anyway have to go get some therapy on my knees right now...
just wanted you to know I am paying attention to you and the others
that have replied to my question/s
gotta go....
Norm.